Inertial sensors (e.g., accelerometers, gyroscopes, inclinometers, etc.) are increasingly used in computer-assisted surgery for numerous reasons. Off-the-shelf inertial sensors are relatively inexpensive and may produce results of sufficient precision and accuracy for orthopedic surgery applications.
A common trait of inertial sensors is that they often do not provide positional information but, rather, simply orientational information, as they operate relative to gravity or by measuring accelerations. Therefore, methods must be devised to create bone references and tools using inertial sensors taking into consideration the absence of positional information.